Photovoltaic (PV) devices operate optimally when incident electromagnetic radiation (EMR) has an energy that corresponds closely to the electron band gap of the PV material. Solar EMR is made up of a continuous spectrum of frequencies and wavelengths. When a photon with an energy less than the electron band gap of a given PV material, the photon lacks sufficient energy to move the electron from its valence band into the conductive band, and the PV material produces no electric current. When a photon has an energy greater than that of the PV material's electron band gap, the electron is moved to the conductive band, consuming the energy corresponding to the band gap, and the excess energy (i.e. the difference between the incoming photon and the PV electron band gap) is not utilized and otherwise lost, generally as heat. Using a radiation source having an energy optimized for the particular PV material used in a solar cell array increases the efficiency of the PV material because less EMR is lost or wasted as heat, and more electricity is produced. Because of the rising demand for alternative energy sources, the need for an efficient alternative energy exists. A major deficiency in alternative energy sources, such as solar energy, include low rate of conversion of EMR to electricity.
Therefore, a need exists for a device and method to increase efficiency of PV cells and avoid excess loss of EMR by altering and optimizing the frequency of incident EMR such that energy production in a PV cell is maximized.
Moreover, the frequency of the vibration and the frequency of the radiation are directly related to a temperature of a substance. Typically, the higher the temperature, the greater the speed of vibration and the higher the frequency of emitted radiation. Additionally, heat generally moves from a higher energy (temperature) location to a lower energy location. Thus, constant ambient heat from high temperature locations and low temperature locations is a renewable source of energy. However, the frequency of the radiation emitted by ambient temperature matter is generally below the threshold necessary to produce electricity using a photovoltaic cell.
Therefore, a need exists for a device and method to convert ambient heat into electricity.